Google Professional-Cloud-Network-Engineer Exam With Confidence Using Practice Dumps

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To determine the Pod per node CIDR range, you need to calculate how many IP addresses are required for each node, and then choose the smallest CIDR range that can accommodate that number. A CIDR range of /n means that there are 2^(32-n) IP addresses available in that range. For example, a /24 range has 2^(32-24) = 256 IP addresses.

According to the question, the application team requires a minimum of 60 Pods per node and a maximum of 100 Pods per node. Therefore, you need to choose a CIDR range that can provide at least 100 IP addresses per node, but not more than necessary. A /25 range has 2^(32-25) = 128 IP addresses, which is enough for 100 Pods per node. A /26 range has 2^(32-26) = 64 IP addresses, which is not enough for 60 Pods per node. A /24 range has 256 IP addresses, which is more than needed and wastes IP address space. A /28 range has 2^(32-28) = 16 IP addresses, which is far too small for any node.

Therefore, the best option is B. /25. This is also consistent with the Google Kubernetes Engine documentation, which states that each node is allocated a /24 range of IP addresses for Pods by default, but the maximum number of Pods per node is 1101. This means that there are approximately twice as many available IP addresses as possible Pods, which is similar to the ratio of 128 to 100 in the /25 range.

1: Configure maximum Pods per node | Google Kubernetes Engine (GKE) | Google Cloud

The problem description indicates that VMs in VPC2 receive traffic but their replies don't reach VPC1, especially when a VPN gateway fails. This strongly suggests an asymmetric routing issue, where VPC2's routing table might not be aware of all necessary routes to send return traffic to VPC1, particularly in a multi-region setup with failover. By default, VPC networks are in regional dynamic routing mode, meaning they only learn routes from Cloud Routers in the same region. To ensure that routes learned from one region (where the active VPN tunnel might be) are available globally across the VPC, you need to enable global dynamic routing mode in the VPC that is experiencing the return traffic issue (VPC2 in this case). This allows VPC2 to learn and apply routes from Cloud Routers in all regions, ensuring that even if a VPN tunnel fails in one region, the routes learned from the active tunnel in another region are still available for return traffic.

Exact Extract:

"A VPC network's dynamic routing mode controls whether routes learned by Cloud Routers in one region are available to VMs in other regions. By default, VPC networks are in regional dynamic routing mode, which means Cloud Routers in a region only advertise routes to and learn routes from other Cloud Routers in the same region. This can lead to asymmetric routing issues in multi-region deployments."

"To ensure that routes learned from Cloud Routers are propagated to all regions within a VPC network, you must set the dynamic routing mode to global."Reference: Google Cloud VPC Documentation - Dynamic routing mode